linux/kernel/perf_event.c, branch v2.6.37

perf: Fix off by one in perf_swevent_init()

2010-12-16T10:14:31Z

The perf_swevent_enabled[] array has PERF_COUNT_SW_MAX elements. Signed-off-by: Dan Carpenter Signed-off-by: Peter Zijlstra LKML-Reference: <20101024195041.GT5985@bicker> Signed-off-by: Ingo Molnar

perf: Fix duplicate events with multiple-pmu vs software events

2010-12-08T19:14:08Z

Because the multi-pmu bits can share contexts between struct pmu instances we could get duplicate events by iterating the pmu list. Signed-off-by: Peter Zijlstra Signed-off-by: Thomas Gleixner LKML-Reference: Signed-off-by: Ingo Molnar

perf: Fix the software context switch counter

2010-11-26T14:00:59Z

Stephane noticed that because the perf_sw_event() call is inside the perf_event_task_sched_out() call it won't get called unless we have a per-task counter. Reported-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar

perf: Fix inherit vs. context rotation bug

2010-11-26T14:00:56Z

It was found that sometimes children of tasks with inherited events had one extra event. Eventually it turned out to be due to the list rotation no being exclusive with the list iteration in the inheritance code. Cure this by temporarily disabling the rotation while we inherit the events. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra LKML-Reference: Cc: Signed-off-by: Ingo Molnar

perf: Fix owner-list vs exit

2010-11-18T12:18:46Z

Oleg noticed that a perf-fd keeping a reference on the creating task leads to a few funny side effects. There's two different aspects to this: - kernel based perf-events, these should not take out a reference on the creating task and appear on the task's event list since they're not bound to fds nor visible to userspace. - fork() and pthread_create(), these can lead to the creating task dying (and thus the task's event-list becomming useless) but keeping the list and ref alive until the event is closed. Combined they lead to malfunction of the ptrace hw_tracepoints. Cure this by not considering kernel based perf_events for the owner-list and destroying the owner-list when the owner dies. Reported-by: Oleg Nesterov Signed-off-by: Peter Zijlstra Acked-by: Oleg Nesterov LKML-Reference: <1289576883.2084.286.camel@laptop> Signed-off-by: Ingo Molnar

Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent

2010-11-18T09:37:51Z

perf,hw_breakpoint: Initialize hardware api earlier

2010-11-12T13:51:55Z

When using early debugging, the kernel does not initialize the hw_breakpoint API early enough and causes the late initialization of the kernel debugger to fail. The boot arguments are: earlyprintk=vga ekgdboc=kbd kgdbwait Then simply type "go" at the kdb prompt and boot. The kernel will later emit the message: kgdb: Could not allocate hwbreakpoints And at that point the kernel debugger will cease to work correctly. The solution is to initialize the hw_breakpoint at the same time that all the other perf call backs are initialized instead of using a core_initcall() initialization which happens well after the kernel debugger can make use of hardware breakpoints. Signed-off-by: Jason Wessel CC: Frederic Weisbecker CC: Ingo Molnar CC: Peter Zijlstra LKML-Reference: <4CD3396D.1090308@windriver.com> Signed-off-by: Frederic Weisbecker

perf_events: Fix time tracking in samples

2010-11-10T21:58:39Z

This patch corrects time tracking in samples. Without this patch both time_enabled and time_running are bogus when user asks for PERF_SAMPLE_READ. One uses PERF_SAMPLE_READ to sample the values of other counters in each sample. Because of multiplexing, it is necessary to know both time_enabled, time_running to be able to scale counts correctly. In this second version of the patch, we maintain a shadow copy of ctx->time which allows us to compute ctx->time without calling update_context_time() from NMI context. We avoid the issue that update_context_time() must always be called with ctx->lock held. We do not keep shadow copies of the other event timings because if the lead event is overflowing then it is active and thus it's been scheduled in via event_sched_in() in which case neither tstamp_stopped, tstamp_running can be modified. This timing logic only applies to samples when PERF_SAMPLE_READ is used. Note that this patch does not address timing issues related to sampling inheritance between tasks. This will be addressed in a future patch. With this patch, the libpfm4 example task_smpl now reports correct counts (shown on 2.4GHz Core 2): $ task_smpl -p 2400000000 -e unhalted_core_cycles:u,instructions_retired:u,baclears noploop 5 noploop for 5 seconds IIP:0x000000004006d6 PID:5596 TID:5596 TIME:466,210,211,430 STREAM_ID:33 PERIOD:2,400,000,000 ENA=1,010,157,814 RUN=1,010,157,814 NR=3 2,400,000,254 unhalted_core_cycles:u (33) 2,399,273,744 instructions_retired:u (34) 53,340 baclears (35) Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: <4cc6e14b.1e07e30a.256e.5190@mx.google.com> Signed-off-by: Ingo Molnar

perf_events: Fix for transaction recovery in group_sched_in()

2010-10-22T12:18:27Z

This new version (see commit 8e5fc1a) is much simpler and ensures that in case of error in group_sched_in() during event_sched_in(), the events up to the failed event go through regular event_sched_out(). But the failed event and the remaining events in the group have their timings adjusted as if they had also gone through event_sched_in() and event_sched_out(). This ensures timing uniformity across all events in a group. This also takes care of the tstamp_stopped problem in case the group could never be scheduled. The tstamp_stopped is updated as if the event had actually run. With this patch, the following now reports correct time_enabled, in case the NMI watchdog is active: $ task -e unhalted_core_cycles,instructions_retired,baclears,baclears noploop 1 noploop for 1 seconds 0 unhalted_core_cycles (100.00% scaling, ena=997,552,872, run=0) 0 instructions_retired (100.00% scaling, ena=997,552,872, run=0) 0 baclears (100.00% scaling, ena=997,552,872, run=0) 0 baclears (100.00% scaling, ena=997,552,872, run=0) And the older test case also works: $ task -einstructions_retired,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5 1680885 instructions_retired (69.39% scaling, ena=950756, run=291006) 10735 baclears (69.39% scaling, ena=950756, run=291006) 10735 baclears (69.39% scaling, ena=950756, run=291006) 0 unhalted_core_cycles (100.00% scaling, ena=817932, run=0) 0 baclears (100.00% scaling, ena=817932, run=0) 0 baclears (100.00% scaling, ena=817932, run=0) Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: <4cbeeebc.8ee7d80a.5a28.0d5f@mx.google.com> Signed-off-by: Ingo Molnar

perf_events: Revert: Fix transaction recovery in group_sched_in()

2010-10-22T12:18:27Z

This patch reverts commit 8e5fc1a (perf_events: Fix transaction recovery in group_sched_in()) because it had one flaw in case the group could never be scheduled. It would cause time_enabled to get negative. Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: <4cbeeeb7.0aefd80a.6e40.0e2f@mx.google.com> Signed-off-by: Ingo Molnar